Hydrogen fuel

Just a quick point to clear up some of your confusion.

When hydrogen is 'burnt', it combines with oxygen to produce water. There are no high-energy free hydrogen atoms left. Same process in a fuel cell.

No hydrogen will escape. Sleep easy.

Thanks, John,

But do you have data to back your comment up? How can we be sure every single Hydrogen atom react completely with oxygen? As I mentioned before, on the entropy standpoint, complete combustion happens only in ideal situation? We all know hydrogen burns with oxygen to form water! But we are not sure if all hydrogen could be burnt?

Actually I have more worries than just the chemistry and physics. There must be commercial drive to say my worries are not justified, but I am not going to take it lighten-hearted!

I wish there are data to show that you are correct, or everyone should wake up and make a fuss on this!

Cheers,

AC Wing.

OK, given I've made a mistake and somehow let the odd hydrogen atom go - the mean free path in air at STP (that is, the distance it will go before bashing into another particle in air at standard temperature and pressure) is about ¹/₁₀₀₀ mm.

Please be assured, it's not going to go far. And it certainly won't get away.

Pax vobiscum.

But are we talking about Hydrogen escape from a very high temperature and pressure combustion processes? I mean not at STP!

As far as hydrogen is concerned, especially when we are talking about hydrogen from fuel cells, that might have electron depleted, attenuation length may be a better choice to consider. Let's assum that you are right in using mean free path, as clearly defined in the name, it is a MEAN value, showing that there are larger and smaller free path. Assuming again, the mean free path, l is correctly used here, the concentration of a beam of exhausted gas from the back of such a car is given by: Beer-Lambert law : I = Io e^-(x/l),

Where I is the concentration at x from the exhaust pipe,

l is the mean free path and

Io is the original exhaust concentration, when they are expelled from the pipe.

Then, we must note, no matter how small l, the mean free path is, or how big x is, I never goes to zero! i.e. there must be some hydrogen escape from the earth even if x is a point high in the space!

In real life, Hydrogen might bump into its own kind of atoms or atoms of other kind, it might be stop for a while, but it would be under constant Brownian motions. As being lighter (the lightest element), it would be squeezed to the top of the atmosphere, where the velocity of escape is low! What would happen? Hydrogen might not be able to escape because it is shot out from car exhaust, but incomletely combusted hydrogen just might not be able to react with other things to stay behind, even when they are bump into other particles!

No matter how little the amount would be, even a single atom is lost to the space a time of cars being used, it is not acceptable because the result would then be disastrous, especially when there are billions of cars running for many many times!

And, we must not ignore the fact that, Hydrogen is one of the most abundant element in the space!

Cheers,

AC Wing.

"As far as hydrogen is concerned, especially when we are talking about hydrogen from fuel cells, that might have electron depleted,"

I believe that when you strip the electron is stripped from an hydrogen atom (molecule) all you have left is a free proton, not any thing left of that poor old hydrogen atom!

Proton so formed might recombine with electron to form hydrogen, hydrogen so formed might follow what we have discussed, either reform water, that would be great; or stay as hydrogen, and escape....

Proton might also stay as it is and escape even easier because of its smaller size!

Hydrogen escape is something we are worrying! Any further good news on this!

AC Wing.

Interesting topic. Too close to my bedtime to do much math tonight. So just a non-mathematically backed up statement.

Hydrogen fuel cells are great devices, however there is a net loss in energy conversion. Ignoring for now the small amount of electricity generated by solar, nuclear, wind etc. far more hydrogen will be liberated in the production of electricity to to perform electrolysis ,than I believe could be lost into space.

Water vapor is constantly being added to the atmosphere by geological and astronomical events. It's a big planet, with lots of water, one way or the other I'm going to speculate that something else kills us before we run out of water.

Again nothing but speculation, I believe fuel cells will be nothing but a stopgap technology as far as automobile transportation. If I remember right, hydrogen fuel cells run about 45% efficiency, at least that's what I remember reading years ago. Hopefully battery technology will continue advancing as they offer much higher net efficiencies.

Great topic however. Found this link it seems some more information may be forthcoming in some planned experiments for Mars probes.

http://space.newscientist.com/article/dn12693-earths-water-brewed-at-home-not-in-space.html

I believe another qustion to ask is where do es Hydrogen come from? Is it solely from the Sun (I consider this unlikely), is it from the sub-surface decay. Geologists have indicated that is the source of oxygen, which is higher up the scale of planetary evolution.

If we look up a fine night sky, it is not hard for us to spot beautiful meteorites, and it is not surprise that some of them carry water, as there are so many icy meteorites we have found. We know well now that there are plenty of Hydrogen in the space, I believe that we shouldn't be surprise also that if the Earth's gravitation catch some. As I mentioned before, incomplete combustion and other mechanism would give rise to internally generated Hydrogen! In short, we can be quite sure that there are hydrogen generated internally on Earth that some of them leave the Earth for good, and there Hydrogen entering the Earth from outer space.

The point that catch our concern here is, if we generate hydrogen that the rate of them leaving the Earth is higher than that entering to us, we have serious trouble! We do not know how much water is entering to us, and how much water are generated on the Earth! On top, we just do not want any irreversible process of losing water for good! Right?

Hi YWRoadRunner, thanks for the very related and informative reading. Agree with you that Hydrogen fuel cell is not very efficient even with the latest development, although lots of improvement might have made. More than just because of efficiency, hydrogen is a more powerful fuel than commonly used fossil fuel, partly deal to the design of engines, hydrogen burning is more exothermic, giving out more heat than commonly use fossil fuels. This would be worsen by the fact that, carbon dioxide concentration on Earth would never go to zero as there are so many living organisms generating them. This coupled with other green house gases like Ozone, green house gases would remain no matter how hard we try, just like a quilt covering the Earth. Yes, we can lower the carbon dioxide emission, like thinning the quilt we used, but it would not be of zero thickness! Now, if we generate more heat underneath the quilt, the Earth is still going to be warmed up even if the quilt is thinnered! Hydrogen escape would just add one more serious problem, drying the earth, especially with the potentially billions of cars to do the same thing. I remember driving on M25, London, for hours we just could not move far and people told me that it was the largest car park on Earth. With so many of cars cramping together, emitting incompletely combusted hydrogen, chance for these hydrogen to combine with oxygen is further lowered as they all struggle for oxygen in close vicinity that would hasten the possible hydrogen escape!

The solution to Global warming is therefore NOT as simple as switching to a more powerful fuel, or simply lower the emission of carbon dioxide. We have to do lots of different things. Lowering the carbon dioxide emission is definitely something helpful, switching to use hydrogen fuel is doubtful and should be monitored as I said before.

Improving engine efficiency, use of batter cars, or improve the compressed air engines, growing more efficient green plants are all possible solutions!

Depletion of Oxygen is of course something terrible, but with the internal combustion engines, we comfortably know that, Oxygen are recycled during the photosynthesis process of green plants!

Really appreciate all your inputs! I am looking forward to more ideas.

Cheers,

AC Wing.

Another too late for the math and just not enough interest to do all the work later but I think you will find that the solar wind puts more Hydrogen into our atmosphere than escapes into space. And as said tons of space dust and ice/water land on this planet every day. A small comet every few hundred years fixes any losses and puts a dent in the local fauna for non-competition areas.

Brad

You might be right but I believe there still are mechanism that we human / or at least me (I would definitely love to know if anyone can tell me more!) do not completely understand, if the solar wind has a lot to give us, it should be Helium, right? But, this is one of the most scarce element on earth, where have they gone?

If we really receive lots of Hydrogen, we don't find them in air. If they react with Oxygen to form water and/or react with Nitrogen to form amonia, then Oxygen and/or Nitrogen should be removed from air and their relative composition in air should be altered as 3 hydrogen atoms would combine with one of that of nitrogen but only 2 hydrogen atoms is necessary to remove one oxygen atom; however they remain relatively constant for centuries already! Our sea and land does not turn very alkali...

If it is free hydrogen in air that escape, we probably would not bother! You might be right that hydrogen from solar wind enter the earth but they might leave at the same time, making their near absence in our atmosphere! But, if it is the hydrogen that are splitted from water molecules that leaves us, especially with billions of engines doing that days and nights, then it should be a real threat to our existence, because losing those hydrogen would mean losing water, drying off the planet!

Have I neglected something or there are things not known to me and I should consider? This is exactly why I put forth this vigorous discussion and try to find out the truth, appreciate all inputs!

My believe is, we don't rely on something that we are not sure and at least, we are all better off maintain our believe in recyclable technologies! Comments please!

Cheers,

AC Wing.

we are all better off maintain our believe in recyclable technologies! Comments please!

How about sustainable instead of recyclable?

Brad

The terms "renewable", recyclable" and "sustainable" flashed across my mind when I was typing the previous reply! Choice of using "recyclable" was not basing on any clear scientific criteria except I just wanted to be more specific.

If recyclable is not always possible, sustainable and renewable are surely preferred than non-reversible breakdown of stuff like splitting water to Hydrogen that would esccape! Seriously, tones of particle from Sun might sound a lot, but compared with the amount of petroleum we burnt everyday, or the potential amount of water we are going to burn, it is peanut!

Cheers,

AC Wing.

space isn't entirely empty .. even without the solar wind the earth sweeps up tons of hydrogen a second. i read it in an electronics magazzine years ago .. it must be true.

we will NEVER run out of hydrogen even if we pumped it into space, probably just pick it up again next lap .. awful lot of H2's in the ocean for a start.

as for helium .. guess we will need to assemble it from hydrogen if we really start running out.

Oh, that's great, but where could we find these H2? Any data to support?

Do you mean we can start to use up the ocean then H2 from space?

Here is what YWRoadRunner recommended previously to read,

http://space.newscientist.com/article/dn12693-earths-water-brewed-at-home-not-in-space.html

It is always helpful to have different idea, yet we must digest them carefully, so data would definitely help!

Cheers,

AC Wing.

In truth hydrogen has a great dislike in existing by it's self. It grabs hold of just about any other molecule that happens by. I don't believe that using hydrogen fuel, either hydrocarbons, rocket fuel, or fuel cells, that any free hydrogen atoms will get all the way through our atmosphere without it grabbing hold of another atom.

The hydrogen is not used up it just combines with another atom and forms a new molecule.

I think there are at least 3 things that are confused.

1. When hydrogen atom combines with hydrogen atom to form hydrogen molecule, it is still hydrogen which we should be able to find them out if they exist, but at leastthis is not the case in our atmosphere! That's why I said that there may still be mechanism that we do not understand completely, if there are!

2. When hydrogen combines with other things to form molecule, it is no more hydrogen, it is another chemical compound. Let's say it combines with Oxygen to form water, then it is now water, not hydrogen. We've discussed this before and concluded that is not likely because that would selectively remove oxygen from air and change the relative composition of air which is not the case, please refer to discussions above.

3. Free hydrogen molecules is itself not a useful fuel because of its low energy density! The energy required to collect them and compress them together to give any meaningful energy output would be far more than it can give out! That's why people are using water as the source of hydrogen fuel! It is compact and it save lots of effort from collecting and compressing them! This is also why spaceship cannot use hydrogen in the space as fuel by far, we still haven't got the kind of technology to do that yet! So, we can forget about free hydrogen in air/space, they are almost absent in the air anyway!

Unless we can guaranttee complete recombination of hydrogen and oxygen to form water (read above discussions please), or splitting water in a non-reversible manner is really dangerous!

It would not be helpful to be emotional, although hydrogen fuel cell sound such a promising fuel just like fossil fuel has once been, which was once brought around by experts and thought to be great, and it has been great by far, but it is hurting the Earth! Although many experts said it is good, we, as part of this earth must be sensible enough to save us from being screw up! How many times there is no experts and genius behind disasters? How many experts and genius were there to invent the sub-prime mortgage that lead the world to the present crisis?

Honestly, as engineers and scientists, we better use the wisdom God gives us rather than take things for granted, not even it is said in Bible! What happened to Galileo when pointed out the Earth revolves round the Sun, not the other way round?

Using up the Ocean is disastrous! If that could be allowed, we could either have come to cease to exist, or we might even have technology to live on the Mars!

Cheers,

AC Wing.

"Using up the Ocean is disastrous! ..."

Please consider some simple sums:

Say the population of Earth physically capable of driving a car is 5 x 10⁹. Give each of them a car, which runs on seawater, doing, say 5km/l. Let each of them drive an average of, say, 20,000 km/year. That's

5 x 10⁹ x (20000/5) = 2 x 10¹³ litres/year, a lot of water!

BUT the volume of water in the Earth's oceans is over 1 x 10¹⁸ litres. Which means that if all the seawater used by those cars was 'lost in space', there would still be enough to last (10¹⁸/(2 x 10¹³)) = 50,000 years!

Great! it is interesting.

Questions: Shall we use this mighty fuel in aeroplanes? Ocean liners? Other industrial applications... I am not sure, but I am sure that human are energy thirsty, we keep looking for new energy sources and use as much as we can get hold of!

One thing worth mentioning is, sea water is poisonous to be split directly, chlorine, a killer gas would form! One of the way to get around it is use microwave to split the salty water, then it would leave the salt under changed, only water molecule would be split. In other words, we would have one more demand for energy, more water would split for this application!

What would happen if the salt concentration in sea rises by 1/1000, 1/100, 1/10? What would be the impact on the ecosystem?

Is the 5km/l a bit optimistic! There was a series on the Discovery Channel saying that they need a lot of energy to split water for hydrogen just for one journey (I could not recall how much), Anyone could please provide some practical data? One of the inhibiting factor that stop me from driving juicy cars is the sky high petroleum cost (of course those cars themselves are too expensive as well), but hydrogen is kind of fuel that is definitely capable of delivering the kind of excitement which many dreams to enjoy! Should that be considered as well?

Surely, we don't just boil all water away! As so many comments said, most hydrogen would recombine with oxygen to form water, but there is just no guaranttee that they would all do that. But, from the entropy stand point, from the composition of air and from the richness of hydrogen in the space, from comments from scientists (there always are opposite ideas from them), escape of hydrogen is possible.

Rise of salt concentration is but one of the dangerous phenomena that we might encounter if we lost water from this planet. No one would be sure how long we can last if water is losing from Earth, no one want something that would be, may be, could be... happening, we all don't want dangers from happening, that's why we want to know!

Don't forget as mentioned before, Green house gases can by no means to be completely removed, and burning hydrogen is even more exothermic! Given both happens side by side, Global warming is the thing we want to avoid, would definitely be worsen!

I feel better now, although I know that the danger we mentioned would not endanger my personal existence, our spices might be killed LATER! Is this what we want?

Cheers,

AC Wing.

You forgot 99.99% H2 used or more recombines making water. (probably more than gas and diesel) so 50,000 X 10,000 or 500,000,000 years. Then subtract from the system sulphuric and Nitric acids etc. hydrogen content that comes from fossil fuels not burned.

Of course the sun is 10% brighter right now so the lost pollution will jump the mean temp 2 deg. c. or 5 deg.f.

Sorry but the sky is not falling, well only 30,000 tons a year of asteroids and comets (mostly dust). Of which a percentage is water. When NORAD went active it is a wounder the U.S. didn't start the Nuclear war. A couple times a month a re-entry of something large enough to trip the system that would put them on high alert and prepare to launch. Took them a little while to figure out it was meteors exploding in the upper atmosphere. Looks like we pasted another test of self annihilation.

Brad

Does this change the position of our discussion?

Bulky as hydrocarbons from fossil, molecules escape from complete combustion is obvious, let alone to say the almost smallest proton (Hydrogen stripped with electron) from Hydrogen fuel cell). Where is this 99.99% from? I did not forget it, we actually are talking about this escaping hydrogen is posting us a threat, not to us in our generation but to generations later!

50,000 years was estimated basing on assumption of 4X10e9 people would drive, on 5km/l, while human might well died off before probably a 10th of the sea was dry off, our population is still on the growth (at certain place, this is multiplying by geometric ratio), adding on the growing demand for energy, the industrial, traffic and other domestic applications..., each of these would probably decrease the figure 50,000 by a order of half or to a 10th, we must play safe! What is hydrogen fuel gives only 2.5km/l? What if the industrial use of energy is like a 100 times of that of fuels consumption in private car usage? What about traffic consumption of other categories, including Aerospace, probably space travel very soon? Cargo and ocean going consumption can be neglected? What about we soon drive and fly in the same vehicle? How many zeros in the calculation are going to be knocked down?

All these hypothetical data can give some insights, but using them for making decision would really be terrible!

After all, you are saying yes, there is hydrogen escape, but the amount is small although this is a much smaller sub-atomic particle; and

there would be more water entering the earth than would be dried off!

Then, why don't we just get some real data, say monitor this hydrogen fuel cell exhaust contents and temperature for a start (as I started this discussion)?

And, in all these agruements, the effect of hydrogen fuel on Global warming, as being a more exothermic fuel and green house gases could never be eliminated, is neglected. Why should we want to change to use fuel other than fossil fuel to start with?

Oh, the sky is not falling, and we are all dying, at least would die one day! Why should we bother to take so much trouble is find this or that out! We better all play safe, right?

I want to summarize what we have discussed so far, if there are new idea, please post them!

Cheers,

AC Wing.

In a way that's my point. What are the actual numbers. Not opinions.

I'm sure studies have been done on space dust composition that falls to earth. On planet outgassing atmosphere to space.

My opinion is we don't loose anything to hydrogen use. I have studied the chemistry, physics and different systems out there more than most. Electrons are conserved because the system is a circuit. Mater is conserved because our solar system is a gravity well. even the solar wind piles up at the outer fringes of the system. Hydrogen is the most abundant element. Even the Moon is covered in it.

Neutrinos on the other hand...

Brad

A lot of people have different points of views! May be this is true, may be that is true, I am not in a position to lecture what is the proper way to study! There is no hurt to think, to suggest and to doubt in creative ways! There have always been people proposing conflicting theories about this Universe, Spontaneous Generation, Big Bang theory, Contraction and then Bang again, and there have always been people supporting one or the other! MATTERs enter and leave the Earth is but one example and I support both, to the extend that I believe they are almost in equiplibrium, i.e. matters are entering and leaving the Earth at nearly the same rate. I do not doubt for a moment that there have been studies made on related subjects and I know that many of them are far from conclusive! Hawking has just recently said Black holes are not totally black!

I've put forth my views and support reasons in previous discussions. Abundant of hydrogen in the Solar Nebula means that are emitted by the Sun, but not "consumed" by other planets and Stars, not totally at least. Relative composition of our atmosphere has NOT changed for centuries, hydrogen would differentially alter the concerned composition if they enter the Earth to combine with O₂ or N₂, H₂ are almost absent from our atmosphere. These are pointing to direction opposite to that this element is entering to enrich our source of H₂. If H₂ enters the Earth and react with other element/compound to form another compound (like one of the Guest said), then it would remove that element/compound and increase the concentration of the concerned compound, which is NOT the observed fact. The terrible thing about this school of thinking is that most likely candidates it reacts with are O₂ and N_2, what would happen when these two elements are removed from our air?

On top, free hydrogen is not useful as fuel with our current technology, and it also added to warming up our Globe.

How much water and other material entering to our planet, we don't know. My best support to this is to study it in detail and find out related data! It can be a subject of discussions, but no data for decision making yet!

The reasons for commercial or functional leaders run out of liquidity are most likely to be ignorance, they overlook consumption when they budget their expenses or they are too optimistic about their expenses! I quoted one of the hydrogen expenses would be private cars, but that should not be taken as the only consumption that we'll deal with using whatever new generation fuel!

Your opinion is well noted, but just cannot be taken for granted. With the data and facts I pointed out (e.g. there are lots of hydrogen in close by Nebula but not useful as fuel for reason discussed previously), I believe facts are convincing that lose of hydrogen to space is more acceptable (read previous discussions please!), Beer-Lambert law (with boundary conditions like the atomic mass, velocity of escape…) also pointed to this fact.

I hope all participants would help by providing at least some reliable data and source of data, or, at least good reasoning, commonly accepted principles and theories, so as to help our discussions to be more meaningful. Taking things for granted is not my practice as there might be so many different reasons that people might behave erratically, commercial drive is one of the possible root causes.

Dear Guru, it is nice to have somebody who study a lot to join our discussion and I belive, with the rich abundance of CR4 readers, we all know who knows what! Making judgment in science and engineering has always been collecting information, analyzing data and then make decisions and act on them. Pure emotional or passionate appeal to trust is probably God's divine right which I cannot grant! I'll trust whoever who can supply unequivocal data, or at least well accepted principles and theories, and I am happy to believe that we are safe to use hydrogen fuel, provided it really is shown by facts!

AC Wing.

I believe that God is great, it might be even as great as we as human cannot fully comprehen his/her appearance and the form of his/her existence. I therefore intend to use the wisdom he/she gives us, and don't tell me what is told in Bible and then said error are made by human! Show me data and I believe they are hints leave by God!

One more crucial point:

Matter are conserved in the Universe, but there are Stars died, dying and to die, and there are new Stars born! There are matters being drawn out from Star systems, there are matters thrown onto another Stars! Matter can still be conserved even if matters are leaving the Earth to the outer space as far as a complete system is considered! Be very careful with this please!

How can we be certain that we are not losing anything!

AC Wing.

I believe that God is great, it might be even as great as we as human cannot fully comprehen his/her appearance and the form of his/her existence. I therefore intend to use the wisdom he/she gives us, and don't tell me what is told in Bible and then said error are made by human! Show me data and I believe they are hints leave by God!

Don't get me wrong, although it is always data help making decisions, that should not stop novelty idea being posted. Appreciate people from all walk to post what they know, just like UV Guru.

It might take me sometime to generalize all post idea and concepts, with pros and cons, I am listen in the mean, all idea are welcome!

Cheers,

AC Wing.

Hi Mates,

It is nice to see there are more advocation in connection to hydrogen fuel. I was going to summarize our discussions so far but, I end up in finding providing the following links more informative!

For your perusal:

http://www.colorado.edu/news/releases/2005/156.html

hydrogen is not a very clean energy source:

http://www.ecoearth.info/shared/reader/welcome.aspx?linkid=37513

"Skeptics also point out that because of the hydrogen molecule's small size and volatility, it is an extremely leak-prone gas that must be closely monitored."

http://forestpolicy.typepad.com/ecoecon/2006/10/ecological_econ.html

'Imagine that we are enclosed in a bulb that has a diameter of 20,000 miles centering on the Earth's core. As it rides around the sun and with the solar system through the empyrean vastness, meteors enter it, spacecraft are sent out from it, hydrogen atoms escape from it; nuclear explosions annihilate dust within it, but for all practical purposes, the weight and composition of matter remain fixed in this 3-D surface. Modern thermodynamics distinguishes among three kinds of systems:..."

Again, many of these do not included any specific data, but worth noting. Their original essay might well have better proof of the subjects they said.

I quote them just for the sake letting people with opposite idea to know, that my worries were not totally imaginary!

Any more different idea?

Cheers,

AC Wing.